FE Fetal Cardiac Anatomy & Development 2 — Questions and Answers
Question 1: During which embryonic week does cardiac looping occur, establishing the left-right axis of the heart?
- Week 3
- Week 4–5 (Correct answer)
- Week 6–7
- Week 8–9
Correct answer: Week 4–5
Cardiac looping occurs between weeks 4 and 5, transforming the straight heart tube into an S-shaped structure that determines left-right cardiac asymmetry.
Question 2: Which structure connects the pulmonary trunk to the descending aorta in fetal circulation?
- Foramen ovale
- Ductus venosus
- Ductus arteriosus (Correct answer)
- Sinus venosus
Correct answer: Ductus arteriosus
The ductus arteriosus shunts blood from the pulmonary trunk to the descending aorta, bypassing the unexpanded fetal lungs.
Question 3: The normal fetal cardiac axis points toward which direction relative to the spine?
- Rightward at 45° (dextroposition)
- Leftward at approximately 45° (levocardia) (Correct answer)
- Directly anterior
- Posteriorly toward the spine
Correct answer: Leftward at approximately 45° (levocardia)
The fetal cardiac axis normally points to the left at approximately 45° ± 20° relative to the anterior chest wall.
Question 4: What is the primary source of oxygenated blood returning to the fetal heart from the placenta?
- Superior vena cava
- Pulmonary veins
- Umbilical vein via ductus venosus (Correct answer)
- Coronary sinus
Correct answer: Umbilical vein via ductus venosus
Oxygenated blood from the placenta travels through the umbilical vein and preferentially streams through the ductus venosus into the inferior vena cava.
Question 5: Which embryonic structure gives rise to the atrial septum primum?
- Bulbus cordis
- Endocardial cushions
- Primitive atrium wall (Correct answer)
- Truncus arteriosus
Correct answer: Primitive atrium wall
The septum primum grows downward from the roof of the primitive atrium toward the endocardial cushions, partitioning the common atrium.
Question 6: In a normal four-chamber view, the interventricular septum should appear at approximately what angle to the fetal spine?
- 0–10°
- 15–25°
- 45° (Correct answer)
- 90°
Correct answer: 45°
The interventricular septum normally forms approximately a 45° angle with the fetal spine in the four-chamber view.
Question 7: Which valve lies at the junction of the right atrium and right ventricle and is offset apically compared to the mitral valve?
- Pulmonary valve
- Aortic valve
- Tricuspid valve (Correct answer)
- Eustachian valve
Correct answer: Tricuspid valve
The tricuspid valve inserts more apically on the interventricular septum than the mitral valve, a key landmark for distinguishing right from left ventricle.
FE Fetal Cardiac Anatomy & Development 2
During which embryonic week does cardiac looping occur, establishing the left-right axis of the heart?